在系统调用和命令提示符中调用“ cd”之间的区别
[英]difference between calling 'cd' in system call and command prompt
问题描述
I am using a linux command prompt and I have noticed a difference when using the command 'cd' in the command prompt and using the command as an argument of the system call in a C program. 
我正在使用linux命令提示符，并且在命令提示符中使用命令“ cd”并将命令用作C程序中系统调用的参数时，我已经注意到了差异。
When I use the command prompt, the directory changes to the directory in the $home environment variable, but if I call it using the system call, then the directory doesn't change? 当我使用命令提示符时，目录会更改为$ home环境变量中的目录，但是如果我使用系统调用来调用，那么目录不会更改吗？
Why is this happening? 为什么会这样呢？
1 个解决方案
解决方案1
6 已采纳 2013-01-20 03:08:37
The cd command is a shell builtin -- when it is executed by a shell script or on the command prompt, it is interpreted by that shell directly, and changes the working directory of the shell process. cd命令是Shell内置的-当它由Shell脚本执行或在命令提示符下执行时，它将直接由该Shell解释，并更改Shell进程的工作目录。
When you run a cd command from within a system() call, the command is passed to a shell subprocess, and changes the working directory of that process, which promptly exits. 当您从system()调用中运行cd命令时，该命令将传递到Shell子进程，并更改该进程的工作目录，该目录会立即退出。 The working directory of the parent process is left unchanged. 父进程的工作目录保持不变。
If you need to change the working directory of the current process, call chdir() directly. 如果需要更改当前进程的工作目录，请直接调用chdir() 。 Note that you can't change the working directory of other processes (the child process is independent of its parent). 请注意，您不能更改其他进程的工作目录（子进程独立于其父进程）。
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